首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   36632篇
  免费   5457篇
  国内免费   843篇
耳鼻咽喉   12篇
儿科学   389篇
妇产科学   339篇
基础医学   3979篇
口腔科学   48篇
临床医学   3087篇
内科学   1054篇
皮肤病学   136篇
神经病学   153篇
特种医学   1803篇
外国民族医学   74篇
外科学   4787篇
综合类   4742篇
现状与发展   6篇
一般理论   1篇
预防医学   1723篇
眼科学   56篇
药学   2069篇
  26篇
中国医学   650篇
肿瘤学   17798篇
  2024年   104篇
  2023年   548篇
  2022年   1248篇
  2021年   1865篇
  2020年   1721篇
  2019年   1582篇
  2018年   1482篇
  2017年   1504篇
  2016年   1631篇
  2015年   1978篇
  2014年   2465篇
  2013年   2676篇
  2012年   2057篇
  2011年   2238篇
  2010年   1684篇
  2009年   1614篇
  2008年   1678篇
  2007年   1752篇
  2006年   1788篇
  2005年   1589篇
  2004年   1318篇
  2003年   1248篇
  2002年   1057篇
  2001年   937篇
  2000年   735篇
  1999年   641篇
  1998年   515篇
  1997年   499篇
  1996年   410篇
  1995年   343篇
  1994年   246篇
  1993年   222篇
  1992年   195篇
  1991年   185篇
  1990年   135篇
  1989年   118篇
  1988年   115篇
  1987年   102篇
  1986年   98篇
  1985年   128篇
  1984年   90篇
  1983年   67篇
  1982年   78篇
  1981年   81篇
  1980年   45篇
  1979年   41篇
  1978年   29篇
  1977年   20篇
  1976年   18篇
  1975年   6篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
《Cancer radiothérapie》2022,26(4):611-615
In order to provide more convenient irradiation regimens for patient comfort, radiation facility organization and health expenses, new hypofractionated protocols have been evaluated. Moderately (dose/fraction: 2.3 to 3 Gy), then ultra (dose/fraction: 5.2 to 6.1 Gy) hypofractionated irradiations were first validated. The current question is: is it possible to go forward using extreme hypofractionated regimens (EHR) based on 1 to 3 fractions. Different irradiation techniques are under investigation. However, brachytherapy remains the smartest way to deliver a high dose in a small volume. We report prospective and retrospective study results which evaluated EHR for breast and prostate brachytherapy. While oncological outcome and toxicity profile appear extremely encouraging for low-risk breast cancer after a 1 to 4 fractions (6.25 to 20 Gy/fraction), the use of a single fraction of 19 to 23 Gy appears debatable for prostate cancer. Brachytherapy represents an emblematic example of EHR but longer follow-up and more mature results are awaited in order to specify the right indications and refine the EQD2 calculation method including new biological and technical factors.  相似文献   
2.
3.
4.
5.
Breast core biopsies are a standard component of the triple approach that includes clinical examination, imaging and tissue sampling. Conventional cores, diagnostic vacuum assisted biopsy and vacuum assisted excisions are established methods for sampling and managing breast lesions. It is important to be aware of the potential pitfalls in the technical handling and interpretation of the limited core biopsy samples. Here, we present a clinically oriented, well illustrated overview of the common diagnostic pitfalls based on the author's diagnostic and second opinion practice, emphasize the value of clinicopathological correlation and provide histological tips and clues with useful immunohistochemistry to aid the reporting pathologists in their daily interpretation of breast core biopsies.  相似文献   
6.
7.
8.
Tamoxifen prevents recurrence of breast cancer and is suggested for preventive risk-reducing therapy. Tamoxifen reduces mammographic density, a proxy for therapy response, but little is known about its effects in remodelling normal breast tissue. Our study, a substudy within the double-blinded dose-determination trial KARISMA, investigated tamoxifen-specific changes in breast tissue composition and histological markers in healthy women. We included 83 healthy women randomised to 6 months daily intake of 20, 10, 5, 2.5, 1 mg of tamoxifen or placebo. The groups were combined to “no dose” (0-1 mg), “low-dose” (2.5-5 mg) or “high-dose” (10-20 mg) of tamoxifen. Ultrasound-guided biopsies were collected before and after tamoxifen exposure. In each biopsy, epithelial, stromal and adipose tissues was quantified, and expression of epithelial and stromal Ki67, oestrogen receptor (ER) and progesterone receptor (PR) analysed. Mammographic density using STRATUS was measured at baseline and end-of-tamoxifen-exposure. We found that different doses of tamoxifen reduced mammographic density and glandular-epithelial area in premenopausal women and associated with reduced epithelium and increased adipose tissue. High-dose tamoxifen also decreased epithelial ER and PR expressions in premenopausal women. Premenopausal women with the greatest reduction in proliferation also had the greatest epithelial reduction. In postmenopausal women, high-dose tamoxifen decreased the epithelial area with no measurable density decrease. Tamoxifen at both low and high doses influences breast tissue composition and expression of histological markers in the normal breast. Our findings connect epithelial proliferation with tissue remodelling in premenopausal women and provide novel insights to understanding biological mechanisms of primary prevention with tamoxifen.  相似文献   
9.
10.
孙莉  赵毅 《现代肿瘤医学》2019,(13):2420-2424
三阴性乳腺癌(triple negative breast cancer,TNBC)是雌激素受体(estrogen receptor,ER)、孕激素受体(progesterone receptor,PR)及人类表皮生长因子受体(human epidermal growth factor-2,HER-2)均不表达的乳腺癌。按其功能特征可归纳为5类分子分型:以DNA修复缺陷或生长因子为途径的基底细胞样三阴性乳腺癌;以上皮-间充质转化和肿瘤干细胞为特征的间质样三阴性乳腺癌;免疫调节型三阴性乳腺癌;雄激素受体过表达的管腔/分泌型三阴性乳腺癌;HER-2富集型三阴性乳腺癌。三阴性乳腺癌恶性程度高且异型性较大,其治疗困难且预后较差,内分泌治疗及靶向治疗不敏感。目前很多学者对于三阴性乳腺癌的治疗各有研究,并有临床试验证实下述治疗有效。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号